1. Technical Field
The present disclosure relates to an apparatus and a method for making an electrically conductive element using carbon nanotubes.
2. Discussion of Related Art
Electrically conductive elements, especially transparent conductive elements, are an important element in various electronic devices, such as touch panels, liquid crystal display devices, or field emission display devices.
Conventional conductive elements usually include a substrate and a transparent metal oxide film formed on the substrate. The transparent metal oxide film can be an indium-tin oxide (ITO) film or a zinc oxide (ZnO). However, after being continuously folded, the resistance of the metal oxide films at the folded location will increase, and the mechanical and chemical properties are not good. The metal oxide films are mainly made by vacuum evaporation methods and magnetron sputtering methods. The drawbacks of these methods include complicated equipment, high cost and being unsuitable for mass production. Furthermore, these methods need a process of high-temperature annealing, which will damage the substrate on which the transparent conductive film is formed, whereby the substrate with a low melting point cannot be used for forming the film. Thus, the conventional methods have their limitations. In addition, the metal oxide films are usually electrically isotropic conductive film, which makes the conductive elements are electrically isotropic conductive.
What is needed, therefore, is to provide an apparatus for making a carbon nanotube film with electrically anisotropic conductivity, to overcome the above shortages.